Download or read book Static and Dynamic Behaviour of Transverse Domain Walls in Ferromagnetic Nanostrips written by Emma Lewis and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field Driven Domain Wall Dynamics in Ferromagnetic Nanostripes written by Sascha Glathe and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: I report on the dynamics of magnetic domain walls (DW) in ferromagnetic nanostripes. The investigations were carried out using the giant magnetoresistance effect, while the DW moved in a soft magnetic NiFe layer. This technique enabled me to verify for the first time the so called Walker Breakdown process in single shot measurements. Additionally I investigated the influence of an in plane transverse field (perpendicular to the movement direction of the DW) on the DW dynamics. It turned out that the DW mobility can be significantly increased, because of a change of the DW shape due to the effect of the transverse field. In the course of the single shot experiments I discovered a new kind of DW motion. Under the influence of a transverse field or in comparably wide nanostripes the DW is stretched along its movement direction. This longitudinal elongated DW is only dynamically stable and is a result of the interplay between the exchange energy and the demagnetization energy. The influence of the nanostripe real shape, in particular the shape of the cross section, on the DW behavior was investigated in another part of this thesis. It turned out that one finds different so called critical Walker fields in the same sample. This critical field depends theoretically on geometric and material parameters and thus should be the same for one sample. I could explain these findings with different stray field contribution in the region of the DW in dependence on the magnetization configuration inside the wall. In a last part I investigated the influence of a transverse field on the DW pinning process. Due to geometric imperfections of the nanostripe, e.g. edge roughness, the DW can be pinned to such a defect. I showed that a transverse field decreases the pinning probability of weak pinning sides. However, for strong pinning sites the probability can show complicated dependencies on the DW pinning process.
Download or read book Ferromagnetodynamics written by Thomas Henry O'Dell and published by John Wiley & Sons. This book was released on 1981 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Domain Walls Driven by Interfacial Phenomena written by Satoru Emori and published by . This book was released on 2014 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: A domain wall in a ferromagnetic material is a boundary between differently magnetized regions, and its motion provides a convenient scheme to control the magnetization state of the material. Domain walls can be confined and moved along nanostrips of magnetic thin films, which are proposed platforms for next generations of solid-state magnetic memory-storage and logic devices. In these devices, domain walls must be moved by electric current, rather than by magnetic field, to achieve scalability and lower-power operation. Recent studies have reported efficient domain-wall motion driven by current in out-of-plane magnetized multilayer films with strong spin-orbit coupling. In particular, extraordinary current-driven domain-wall motion has been observed in atomically-thin ferromagnets sandwiched between a nonmagnetic heavy metal and an insulator. Through experimental studies on various sputtered magnetic multilayers, we elucidate the mechanism of such anomalous domain-wall dynamics. We show that conventional current-induced spin-transfer torques, which drive domain walls in thicker films, are negligible in ultrathin ferromagnets. We also show that the Rashba field, often reported in materials with strong spin-orbit coupling, does not contribute to the observed efficient domain-wall motion. The anomalous dynamics instead emerges from the spin Hall effect: a charge current in the nonmagnetic heavy metal generates a spin current, which exerts a torque on spins in the adjacent ferromagnet. This spin Hall torque drives domain walls forward if the domain-wall spins are parallel to the nanostrip axis with a fixed chirality. We reveal that the Dzyaloshinskii-Moriya interaction, arising from spin-orbit coupling and asymmetric interfaces, stabilizes homochiral domain walls in ultrathin ferromagnets. Our findings not only provide a route to bolster current-driven domain-wall dynamics, but also enable new chiral magnetic textures in magnetic heterostructures for device applications.
Download or read book Magnetic Behavior of 360 Domain Walls in Patterned Magnetic Thin Films written by Mark Daniel Mascaro and published by . This book was released on 2012 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: 360° transverse domain walls (360DWs), which form readily from transverse 180° domain walls (180DWs) of opposite sense, demonstrate qualitatively distinct behaviors from their constituent 180DWs and are therefore of interest both from a physics perspective and for their applications in future domain wall devices. This thesis presents experimental and modeling-based investigation of the properties and behaviors of 360DWs including formation, magnetostatic behaviors, and response to field, AC, and DC driving forces. The formation of 360DWs is first examined by simulation in a model nanowire. An injection system capable of producing 360DWs from a wire and an injection pad is presented and its behavior is analyzed both by simulation and experimentally through magnetic force microscopy and scanning electron microscopy with polarization analysis. Next, a model multilayer system is used to demonstrate the magnetostatic behavior of 360DWs, demonstrating a much reduced stray field compared to 180DWs and a strong interlayer pinning behavior that allows the 360DW to act as a programmable pinning site. The richness of this magnetostatic behavior is analyzed experimentally in a rhombic ring system which readily generates 360DWs during reversal. The action of 360DWs is shown to dominate the reversal process, reducing switching fields and showing multiple reversal pathways with a strong dependence on field history. Simulations are used to explore the response of the 360DW to field and DC and AC currents. This highlights 360DW behaviors quite distinct from those of 180DWs, including the inability to be positioned by an applied field and the ability to be destroyed in place. 360DWs are shown to have an intrinsic resonant behavior in the GHz range, the exact frequency of which is broadly tunable by an applied field. Resonance can be excited by an applied AC current, and in conjunction with DC can be used to pin and gate 360DW propagation at a geometric pinning site, using globally applied currents and without impact on nonpinned domain walls.
Download or read book Study of Static Spin Distributions and Dynamics of Magnetic Domain Walls in Soft Magnetic Nanostructures written by Jusang Yang and published by . This book was released on 2013 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The static and dynamic properties of spin distributions within domain walls(DWs) confined by Permalloy nanowire conduits are investigated by numerical simulations and high-speed magneto-optic polarimetry. Phase boundaries and critical points associated with DW spin distributions of various topologies are accurately determined using high-performance computing resources. Field-driven mobility curves that characterize DW propagation velocities in 20 nm thick nanowires are calculated with increasing the width of nanowires. Beyond the simple one-dimensional solution, the simulations reveal the four distinct dynamic modes. Oscillations of the field-driven DW velocity in Permalloy nanowires are observed above the Walker breakdown condition using high-speed magneto-optic polarimetry. A one-dimensional analytical model and numerical simulations of DW motion and spin dynamics are used to interpret the experimental data. Velocity oscillations are shown to be much more sensitive to properties of the DW guide structure (which also affect DW mobility) than the DW spin precessional frequency, which is a local property of the material. Transverse bias field effects on field-driven DW velocity are studied experimentally and numerically. DW velocities and spin configurations are determined as functions of longitudinal drive field, transverse bias field, and nanowire width. For a nanowire that supports vortex wall structures, factor of ten enhancements of the DW velocity are observed above the critical longitudinal drive-field (that marks the onset of oscillatory DW motion) when a transverse bias field is applied. The bias-field enhancement of DW velocity is explained by numerical simulations of the spin distribution and dynamics within a propagating DW that reveal dynamic stabilization of coupled vortex structures and suppression of oscillatory motion in the nanowire conduit resulting in uniform DW motion at high speed. Current-driven and current-assisted field-driven domain wall dynamics in ferromagnetic nanowires have thermal effects resulting from Joule heating, which make difficult to separate the spin-torque effects on DW displacements. To understand the thermal effects on DW dynamics, the temperature dependence of field-driven DW velocity is explored using high-bandwidth scanning Kerr polarimetry. Walker critical fields are decreased with increasing temperature and temperature-induced dynamic mode changes are observed. The results show that Joule heating effects are playing an important role in current-driven/current-assisted field-driven DW dynamics.
Download or read book Handbook of Spintronics written by Yongbing Xu and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.
Download or read book Mathematical Modelling and Scientific Computing with Applications written by Santanu Manna and published by Springer Nature. This book was released on 2020-02-14 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains original research papers presented at the International Conference on Mathematical Modelling and Scientific Computing, held at the Indian Institute of Technology Indore, India, on 19–21 July 2018. Organized into 30 chapters, the book presents the recent progress and the most advanced innovations, trends, and real-world challenges encountered and solutions embraced in the applications of mathematics and scientific computing. The book will be of interests to a wide variety of researchers, students and the practicing engineers working in diverse areas of science and engineering, ranging from applied and computational mathematics, vibration problem, computer science, and numerical optimization to physics, chemistry, biology, electrical, civil, mechanical, chemical, seismology, aerospace, and medical sciences. The aim of the conference is to bring together leading academicians, scientists, researchers, engineers, and industry partners from all over the globe to exchange and share their experiences and research results on various aspects of applied mathematics and scientific computation, like, differential equation, modeling, simulation, dynamical systems, numerical analysis, matrix theory, inverse problems, and solid and fluid mechanics, computational engineering.
Download or read book Handbook of Magnetism and Magnetic Materials written by Michael Coey and published by Springer. This book was released on 2021-11-19 with total page 1679 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook presents a comprehensive survey of magnetism and magnetic materials. The dramatic advances in information technology and electromagnetic engineering make it necessary to systematically review the approved key knowledge and summarize the state of the art in this vast field within one seminal reference work. The book thus delivers up-to-date and well-structured information on a wealth of topics encompassing all fundamental aspects of the underlying physics and materials science, as well as advanced experimental methodology and applications. It features coverage of the host of fascinating and complex phenomena that arise from the use of magnetic fields in e.g. chemistry and biology. Edited by two internationally renowned scholars and featuring authored chapters from leading experts in the field, Springer’s Handbook of Magnetism and Magnetic Materials is an invaluable source of essential reference information for a broad audience of students, researchers, and magnetism professionals.
Download or read book Magnetism of Surfaces Interfaces and Nanoscale Materials written by Robert E. Camley and published by Elsevier. This book was released on 2015-10-27 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 30 years, magnetic research has been dominated by the question of how surfaces and interfaces influence the magnetic and transport properties of nanostructures, thin films and multilayers. The research has been particularly important in the magnetic recording industry where the giant magnetoresistance effect led to a new generation of storage devices including hand-held memories such as those found in the ipod. More recently, transfer of spin angular momentum across interfaces has opened a new field for high frequency applications.This book gives a comprehensive view of research at the forefront of these fields. The frontier is expanding through dynamic exchange between theory and experiment. Contributions have been chosen to reflect this, giving the reader a unified overview of the topic. Addresses both theory and experiment that are vital for gaining an essential understanding of topics at the interface between magnetism and materials science Chapters written by experts provide great insights into complex material Discusses fundamental background material and state-of-the-art applications, serving as an indispensable guide for students and professionals at all levels of expertise Stresses interdisciplinary aspects of the field, including physics, chemistry, nanocharacterization, and materials science Combines basic materials with applications, thus widening the scope of the book and its readership
Download or read book Nanomagnetism and Spintronics written by Teruya Shinjo and published by Elsevier. This book was released on 2013-10-07 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concise and accessible chapters of Nanomagnetism and Spintronics, Second Edition, cover the most recent research in areas of spin-current generation, spin-calorimetric effect, voltage effects on magnetic properties, spin-injection phenomena, giant magnetoresistance (GMR), and tunnel magnetoresistance (TMR). Spintronics is a cutting-edge area in the field of magnetism that studies the interplay of magnetism and transport phenomena, demonstrating how electrons not only have charge but also spin. This second edition provides the background to understand this novel physical phenomenon and focuses on the most recent developments and research relating to spintronics. This exciting new edition is an essential resource for graduate students, researchers, and professionals in industry who want to understand the concepts of spintronics, and keep up with recent research, all in one volume. Provides a concise, thorough evaluation of current research Surveys the important findings up to 2012 Examines the future of devices and the importance of spin current
Download or read book Nonlinearities in Periodic Structures and Metamaterials written by Cornelia Denz and published by Springer. This book was released on 2010-03-11 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical information processing of the future is associated with a new generation of compact nanoscale optical devices operating entirely with light. Moreover, adaptive features such as self-guiding, reconfiguration and switching become more and more important. Nonlinear devices offer an enormous potential for these applications. Consequently, innovative concepts for all-optical communication and information technologies based on nonlinear effects in photonic-crystal physics and nanoscale devices as metamaterials are of high interest. This book focuses on nonlinear optical phenomena in periodic media, such as photonic crystals, optically-induced, adaptive lattices, atomic lattices or metamaterials. The main purpose is to describe and overview new physical phenomena that result from the interplay between nonlinearities and structural periodicities and is a guide to actual and future developments for the expert reader in optical information processing, as well as in the physics of cold atoms in optical lattices.
Download or read book Magnetic Nano and Microwires written by Manuel Vázquez and published by Woodhead Publishing. This book was released on 2015-05-27 with total page 847 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic nanowires and microwires are key tools in the development ofenhanced devices for information technology (memory and data processing) andsensing. Offering the combined characteristics of high density, high speed, andnon-volatility, they facilitate reliable control of the motion of magnetic domainwalls; a key requirement for the development of novel classes of logic and storagedevices. Part One introduces the design and synthesis of magnetic nanowires andmicrowires, reviewing the growth and processing of nanowires and nanowireheterostructures using such methods as sol-gel and electrodepositioncombinations, focused-electron/ion-beam-induced deposition, chemicalvapour transport, quenching and drawing and magnetic interactions. Magneticand transport properties, alongside domain walls, in nano- and microwiresare then explored in Part Two, before Part Three goes on to explore a widerange of applications for magnetic nano- and microwire devices, includingmemory, microwave and electrochemical applications, in addition to thermalspin polarization and configuration, magnetocalorific effects and Bloch pointdynamics. Detailed coverage of multiple key techniques for the growth and processing of nanowires and microwires Reviews the principles and difficulties involved in applying magnetic nano- and microwires to a wide range of applications Combines the expertise of specialists from around the globe to give a broad overview of current and future trends
Download or read book Sensors in Science and Technology written by Ekbert Hering and published by Springer Nature. This book was released on 2022-01-21 with total page 835 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensors are used to measure physical, chemical and biological quantities. The book offers a comprehensive overview of physical principles, functions and applications of sensors. It is structured according to the fields of activity of sensors and shows their application by means of typical examples. Measured variables that can be recorded by sensors are e.g. mechanical, dynamic, thermal, electrical and magnetic. Furthermore, optical and acoustical sensors are discussed in detail in the book. The sensor signals are recorded, processed and converted into control signals for actuators. Such sensor systems are also presented.
Download or read book Handbook of Magnetic Materials written by Ekkes H. Brück and published by Elsevier. This book was released on 2020-11-29 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Magnetic Materials, Volume 29, highlights new advances in the field, with this new volume presenting interesting chapters written by an international board of authors on topics such as spin-orbit torque. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in the Handbook of Magnetic Materials series
Download or read book Nanoscale Magnetic Materials and Applications written by J. Ping Liu and published by Springer Science & Business Media. This book was released on 2010-04-05 with total page 731 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale Magnetic Materials and Applications covers exciting new developments in the field of advanced magnetic materials. Readers will find valuable reviews of the current experimental and theoretical work on novel magnetic structures, nanocomposite magnets, spintronic materials, domain structure and domain-wall motion, in addition to nanoparticles and patterned magnetic recording media. Cutting-edge applications in the field are described by leading experts from academic and industrial communities. These include new devices based on domain wall motion, magnetic sensors derived from both giant and tunneling magnetoresistance, thin film devices in micro-electromechanical systems, and nanoparticle applications in biomedicine. In addition to providing an introduction to the advances in magnetic materials and applications at the nanoscale, this volume also presents emerging materials and phenomena, such as magnetocaloric and ferromagnetic shape memory materials, which motivate future development in this exciting field. Nanoscale Magnetic Materials and Applications also features a foreword written by Peter Grünberg, recipient of the 2007 Nobel Prize in Physics.
Download or read book Superconductivity written by Paolo Mele and published by Springer Nature. This book was released on 2019-08-21 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a comprehensive overview of the science of superconducting materials. It serves as a fundamental information source on the actual techniques and methodologies involved in superconducting materials growth, characterization and processing. This book includes coverage of several categories of medium and high-temperature superconducting materials: cuprate oxides, borides, and iron-based chalcogenides and pnictides. Provides a single-source reference on superconducting materials growth, characterization and processing; Bridges the gap between materials science and applications of superconductors; Discusses several categories of superconducting materials such as cuprate oxides, borides, and iron-based chalcogenides and pnictides; Covers synthesis, characterization, and processing of superconducting materials, as well as the nanoengineering approach to tailor the properties of the used materials at the nanoscale level.
